1. Field of Invention
This invention relates to the web of a paper making machine.
2. Description of the Prior Art
Paper is formed as a web passing over and under successive drying rollers. When a break in the web occurs, the oncoming end of the web wraps itself about the roller around which it is engaged until the rotation of the rollers is stopped.
A series of rollers in parallel relationship in a paper making machine may extend for a city block or more and the rollers are from three to six feet in diameter and from ten to twenty-six feet in length. The web may be traveling up to 1200 feet per minute. The rollers are shut down rapidly when a break in a web occurs but at the point of the break, the forward broken end of the web in wrapping itself about a roller can accommodate to a thickness of layers of the web about a roller up to as much as three and one half inches by the time the rollers are stopped.
When a break occurs, down time is a direct loss. The cost of operation may be on the order of a thousand dollars per hour. Hence down time loss is an important factor.
The tool presently used is a hook at the end of a pole inserted under the layers of wrap about a roller at the far end of a web where the remote edge is engaged and the operator pulls the hook through the web breaking the same apart. This separates the wrapped portion of the web from the oncoming web and said separated portion is pulled off of the roller. The down time here ranges from ten to thirty minutes depending upon the number of layers of the wrapped portion.
The pole mounted hook for removing the wrapped portion of a web is the only known tool to be presently in use and has been in use for many years.
Pole mounted hooks are known to be used in the logging industry and for rupturing walls and ceilings in fire fighting as in McGhee U.S. Pat. No. 2,017,369.